The Ending Effect in the Domain of Gambling: The Effect of Gain-Loss Status on Economic Decision-Making

Previous studies have shown that people prefer risk-taking at the end of gambles, a phenomenon called the ending effect. By using the Guess Gambling Game, we investigated the impact of gain-loss status on the ending effect (Experiment 1) and whether and how this effect may be affected by time reference (Experiment 2) and gender (Experiment 1&2). In Experiment 1, we observed the ending effect only in the gain group. Furthermore, gender differences exist in the loss group behavior, females were more risk-averse than males, and males tend to investment more initially and then reduce their investment in a U-shaped pattern (Experiment 1&2). Next, in Experiment 2, the findings indicated that participants in the gain group made riskier decisions and were willing to allocate more money for additional decision opportunities, irrespective of the time conditions. Additionally, under time-limited condition, participants tended to make more decisions in the final round, aiming to maximize their choices times within the limited time. These results contribute to a better understanding of the boundary conditions surrounding the ending effect in risky decision-making and may offer a scientific basis for mitigating and intervening in irrational decision-making.

Economic decision-making in the continuum between healthy aging and Alzheimer's Disease: A systematic review of 20 years of research

The effect of pathological aging on economic decision-making is a topic of major relevance as impairments in this domain place older adults at increased risk for financial abuse. This review aims to characterize decision-making across the continuum that goes from healthy aging to Alzheimer's Dementia. We included 42 studies comparing patients with Mild Cognitive Impairment (MCI) and healthy older adults, patients with Alzheimer's Disease (AD) and healthy older adults, and patients with MCI and patients with AD. Substantial evidence emerged suggesting that both MCI as AD affect economic decision-making. However, a non-negligible number of behavioural tasks failed to find significant differences between patients and controls, and no differences were reported between patients with MCI and AD. On the contrary, measures of financial capacity reached more robust findings, showing that healthy older adults had better performance than patients, while MCI patients showed better performance than AD patients. This review presents the main conclusions that may be drawn from significant findings, as well as the hypotheses and recommendations for future research.

Two-dimensional reward evaluation in mice

When choosing among multi-attribute options, integrating the full information may be computationally costly and time-consuming. So-called non-compensatory decision rules only rely on partial information, for example when a difference on a single attribute overrides all others. Such rules may be ecologically more advantageous, despite being economically suboptimal. Here, we present a study that investigates to what extent animals rely on integrative rules (using the full information) versus non-compensatory rules when choosing where to forage. Groups of mice were trained to obtain water from dispensers varying along two reward dimensions: volume and probability. The mice’s choices over the course of the experiment suggested an initial reliance on integrative rules, later displaced by a sequential rule, in which volume was evaluated before probability. Our results also demonstrate that while the evaluation of probability differences may depend on the reward volumes, the evaluation of volume differences is seemingly unaffected by the reward probabilities.

The semiotics of the message and the messenger: How nonverbal communication affects fairness perception

Nonverbal communication determines much of how we perceive explicit, verbal messages. Facial expressions and social touch, for example, influence affinity and conformity. To understand the interaction between nonverbal and verbal information, we studied how the psychophysiological time-course of semiotics—the decoding of the meaning of a message—is altered by interpersonal touch and facial expressions. A virtual-reality-based economic decision-making game, ultimatum, was used to investigate how participants perceived, and responded to, financial offers of variable levels of fairness. In line with previous studies, unfair offers evoked medial frontal negativity (MFN) within the N2 time window, which has been interpreted as reflecting an emotional reaction to violated social norms. Contrary to this emotional interpretation of the MFN, however, nonverbal signals did not modulate the MFN component, only affecting fairness perception during the P3 component. This suggests that the nonverbal context affects the late, but not the early, stage of fairness perception. We discuss the implications of the semiotics of the message and the messenger as a process by which parallel information sources of “who says what” are integrated in reverse order: of the message, then the messenger.

The importance of fixed costs in animal health systems

In this paper, the authors detail the structure and optimal management of health systems as influenced by the presence and level of fixed costs. Unlike variable costs, fixed costs cannot be altered, and are thus independent of the level of veterinary activity in the short run. Their importance is illustrated by using both single-period and multi-period models. It is shown that multi-stage veterinary decision-making can often be envisaged as a sequence of fixed-cost problems. In general, it becomes clear that, the higher the fixed costs, the greater the net benefit of veterinary activity must be, if such activity is to be economic. The authors also assess the extent to which it pays to reduce fixed costs and to try to compensate for this by increasing variable costs. Fixed costs have major implications for the industrial structure of the animal health products industry and for the structure of the private veterinary services industry. In the former, they favour market concentration and specialisation in the supply of products. In the latter, they foster increased specialisation. While cooperation by individual farmers may help to reduce their individual fixed costs, the organisational difficulties and costs involved in achieving this cooperation can be formidable. In such cases, the only solution is government provision of veterinary services. Moreover, international cooperation may be called for. Fixed costs also influence the nature of the provision of veterinary education.

Altered economic decision-making in abstinent heroin addicts: Evidence from the ultimatum game

BACKGROUND

The development and persistence of drug addiction has been suggested to involve decision-making deficits. The Ultimatum Game is a widely used economic decision-making paradigm that illustrates the tension between financial self-interest and fairness motives. The behavior of responders in the Ultimatum Game has been associated with emotional reactions and cognitive control abilities, both of which are dysregulated in drug addicts. In this study, we investigated whether this economic decision-making process that involves considerations of social norms is affected by heroin addiction.

METHODS

Heroin addicts (n=17) and demographically matched healthy control subjects (n=18) were recruited to play the part of responders in the Ultimatum Game, during which they decided to accept or reject the monetary offers proposed by strangers. The offers were manipulated by varying the stake sizes and fairness scales. The rejection rates of all of the offer categories, response times, fairness judgments, and impulsivity were compared between heroin addicts and healthy controls.

RESULTS

Compared with healthy subjects, the rejection rates of most unfair offers in the Ultimatum Game were significantly higher under low-offer-size conditions among heroin addicts. In contrast, the most unfair offers were more likely to be accepted by heroin addicts in the high-offer-size condition than by healthy subjects. The ratings of unfairness were equal in both conditions although the rejection rates were different. Heroin addicts had higher scores on BIS attentional/cognitive impulsivity and non-planning impulsivity, but not in motor impulsivity. Rejection rates to most unfair offers under low-offer-size conditions significantly correlated with score on BIS non-planning impulsivity and total score of impulsivity.

CONCLUSIONS

Heroin addicts differentially responded under different stake-level conditions in the Ultimatum Game, with emotional impulses in low-offer-size conditions and selfish motives in the face of high monetary reward. These findings indicate that Ultimatum Game may be associated with heroin addiction and provide a productive new target for enhancing treatment for heroin addiction.